The ultimate goal of the project is to develop a blood test that will significantly improve early detection of lung cancer. A high-performance multiplexed immunoassay platform will be used to evaluate biomarkers that have been associated with lung cancer in research reports. The technology enables this with a very limited amount of sample volume that is available for high quality samples. Mesoscale proposes to apply its Diagnostics electrochemiluminescence (ECl) detection technology to the development of quantitative and highly multiplexed assays for cancer biomarkers. Assays will be carried out using ECl based detection in an array-based multiplexed format on a fully automated high-throughput immunoassay instrument. This platform will be able to simultaneously measure up to 75 biomarkers using only 30 ul of sample (serum, plasma, ductal lavage, saliva and urine), will have ultra-sensitive detection capabilities (analytical sensitivity <1 pg/ml), a dynamic range of 8-logs, and a throughput of 100 to 200 samples per day. As part of the proposed program, we will develop 50 cancer associated biomarker assays for this assay platform. When selecting assays we will focus on biomarkers that have been identified as important by the Clinical Proteomics Technologies for Cancer (CPTC) initiative and CPTC investigators, giving highest priority to biomarkers for which CPTC is developing antibodies. Assay reagents for running the cancer biomarker panels will be provided in a complete consumable kit that will include a 96-well assay plate containing up to 25 immobilized capture antibodies per well (larger assay panels are achieved by spreading the arrays of capture antibodies over multiple wells), and an auxiliary reagent plate containing lyophilized detection antibodies and assay diluents. The assay platform will enable the measurement of numerous cancer associated proteins, and will provide an important tool for the selection and validation of cancer-specific diagnostic biomarkers.